Field of the Invention
The invention relates to a volute mechanism for a blower.
Description of the Related Art
As an element installed on the side of a blower, a manometric interface is a safety device. Although a small volume it has, the manometric interface has a great significance. A negative pressure value is output from the manometric interface and directly connected to the air switch which controls the operation of the whole system. Different loads impose different requirements on the output value of the manometric interface. A typical method is to change a position or a shape of the manometric interface for achieving a qualified output value of the manometric interface. Thus, a blower including a plurality of manometric interfaces with different structures or different positions is produced, thereby improving the production cost and the difficulties in quality monitoring.